Salvador Cepriano is one of the men searching for crude. Cepriano, a shrimper, has been laying out boom with his boat, but he's found that there's no oil to catch.

"I think it is underneath the water. It's in between the bottom and the top of the water," Cepriano said.

Even the federal government admits that locating the oil has become a problem.

"It is becoming a very elusive bunch of oil for us to find," said National Incident Cmdr. Thad Allen.

Skimmers Pick Up Less Oil

The numbers don't lie: two weeks ago, skimmers picked up about 25,000 barrels of oily water. Last Thursday, they gathered just 200 barrels.

Still, it doesn't mean that all the oil that gushed for weeks is gone. Thousands of small oil patches remain below the surface, but experts say an astonishing amount has disappeared, reabsorbed into the environment.

"[It's] mother nature doing her job," said Ed Overton, a professor of environmental studies at Louisiana State University.

Experts: Gulf of Mexico Oil is Breaking Up

The light crude began to deteriorate the moment it escaped at high pressure, and then it was zapped with dispersants to speed the process along. The oil that did make it to the ocean's surface was broken up by 88-degree water, baked by 100-degree sun, eaten by microbes, and whipped apart by wind and waves.

Experts stress that even though there's less and less oil as time goes on, there's still plenty around the spill site. And in the long term, no one knows what the impact of those hundreds of millions of gallons will be, deep in the waters of the Gulf of Mexico.